It is known that a plurality of unit cells are accommodated in one accommodation member to obtain a battery block, and this battery block is used as a high-capacity storage battery. As the accommodation member, an assembly in which cylindrical metallic pipes are spot-welded, an assembly in which a plurality of cases having an accommodation hole are integrally surface-joined, and the like are known (refer to PTL 1).
In addition to this, various related technologies are disclosed (for example, refer to PTLs 2 to 8).
For example, PTL 2 discloses a high-temperature storage battery in which a plurality of storage battery cells are disposed in a predetermined arrangement, and adjacent storage battery cells are partially joined to each other by an external case. PTL 3 also discloses the same invention as PTL 2. However, according to the invention disclosed in PTLs 2 and 3, the storage battery cell is joined to the external case only at several points, and thus it is difficult to suppress local temperature increase by diffusing heat.
In addition, PTL 4 discloses a sodium secondary battery module in which a container main body of an accommodation container assembly is disposed so as to be inserted between thin plates having a semicircular cross section in a lateral direction. However, a joining area between the container main body and the thin plates is small, and thus it is difficult to effectively diffuse heat.
PTL 5 discloses a method of manufacturing a brazing pipe that is used in a header of a heat exchanger, and a method of manufacturing a heat exchanger, but problems in common with the battery block are not mentioned.